[[ Open Video ]]


[B-roll -- Aerial imagery of Ida destruction]
[Photo of the outside of NHC building]
[G16 Geocolor animation of Ida]


Narration: Hurricane Ida will long be remembered for its destructive, deadly path that stretched from Louisiana to the Northeast. 


For meteorologists at NOAA’s National Hurricane Center in Miami, NOAA’s GOES-16 satellite provided the advanced, high-resolution imagery for closely tracking Ida and developing accurate forecasts from start to finish.


Brennan: “We did see in the GOES imagery, the development of that low level center that allowed us to go ahead and call that a tropical cyclone.”


[[Picture of outside of NHC building]]
Narration: Mike Brennan is the branch chief of the hurricane specialists unit at the Hurricane Center. The technology aboard GOES-16 helps forecasters know when a tropical cyclone, like Ida, will strengthen.


Brennan:  “Satellite imagery is one way we can detect the beginnings and continuation of these rapid intensification processes. We can see when an eye begins to form.” [[Sandwich loop of Ida]]


[[Close-up of Ida’s eye]]
Narration: But for Hurricane Ida, it was a case of there being more than meets the eye -- literally.  Within the eye of Ida, GOES-16’s Advanced Baseline Imager saw four mesovortices. A mesovortex is a small-scale rotation in the eyewall of a tropical cyclone and it can be a telltale sign that a storm is getting better organized and intensifying. 


Lindsey: “Typically, we do see mesovortices in strong tropical cyclones.”


Narration: Dr. Dan Lindsey is the NOAA GOES-R program scientist.


Lindsey: “In most cases with strong tropical cyclones, we do see at least one of these vortices, and sometimes up to five or six.”


[[Eye of Ida animation]]
Brennan: “When we started to notice the mesovortex in the eye, that was during a period of time when we were starting to see some pretty dramatic inner core structural changes.”


[[Eye image and b roll of landfalling hurricane, which I have]]
Narration: And with those changes within Ida’s eye, scientists saw its wind speeds go up and its central pressure drop. Both of those changes can make a hurricane's winds and storm surge more destructive and deadly. 


[[Image of GOES-16 3-D model, with zoom of, or point to, ABI]]
With previous generations of GOES satellites, the imager did not have the capability to see the finer details of what today’s GOES can capture.


Lindsey: “We often could not detect these types of mesovortices because they were either too small or too transient in order to be seen...We’re able to actually watch them spin and track them as they move around the cloud field within the eye of the storm.”


Narration: But Ida still had a surprise after it made landfall.  The mesovortices in its eye continued to spin around its eye even while it was over southern Louisiana. 


[[Animation of Ida making landfall]]
Lindsey: “It's quite unusual for us to be able to see mesovortices, say, hours after landfall. The reason is because after a storm comes ashore, it typically loses its fuel source of warm ocean water and begins to weaken fairly rapidly.”


Narration: But Ida’s mesovortices were still visible over land because of what scientists call the Brown Ocean Effect.  Researchers have found that some tropical cyclones can maintain their strength long after landfall--or even strengthen over land-- by tapping into the abundant soil moisture below it.  In some cases, an area of land may have so much moisture contained in it that the hurricane behaves as if it were still over water.


Lindsey: “This is exactly the case in Southern Louisiana, where the storm came ashore. There's lots of warm water covering the area, and we think that the reason the storm remained so strong in this case was due to the presence of that marshy land. It was almost like the hurricane didn't know it was over land—it thought it was still over the warm ocean water—and that is probably the reason the storm remained strong after it came to shore.”


Narration: Hurricane Ida will definitely be a storm for the history books, and its full impacts are still being tallied today. For future hurricanes that threaten the U.S. and elsewhere, NOAA satellites will be our eyes in the sky to help forecasters stay on top of these monster storms.


[[ Fade to full screen NOAA logo ]]